The Principal Research Core's (PRC) mission is to serve as the conceptual architect of the ACISR's research program. To this end, the PRC will promote studies on clinical, psychosocial, and biological predictors of outcomes and moderators of treatment response of geriatric depression and use their findings as a stimulus for developing interventions personalizing care at the patient and the care setting level. A central function of the PRC will be to promote designs that permit testing of interventions at community settings at the soonest possible time that evidence of efficacy permits. The PRC relies on: 1. Investigators with long experience in research planning and complementary expertise in clinical biology, social systems, primary care, home healthcare and rehabilitation studies, biostatistics, and economics with long history of collaboration and ability to integrate their perspectives into cohesive hypotheses;2. an organization that rapidly translates biological and psychosocial findings and clinical experience into intervention studies;3. a track record of independently supported projects (10 funded by NIH and 8 by Foundations in the past year);4. experience in career development of investigators (currently 8 NIMH K Awards are supported by the ACISR);and 5. working research partnerships with the Westchester Geriatric Mental Health Coalition, which includes the County Department of Mental Health, the County Department of Senior Programs and Services, community based primary care practices, rehabilitation hospitals;home healthcare agencies;and other social services. The process of research development and coordination depends on the PRC Management Team developing initiatives that integrate our expertise and research findings with community input on the needs of depressed older adults and the strengths and limitations of the settings that care for them. Developmental Projects 1, 2 and 3, Pilot 1 and 2, and the CNU Research Initiatives presented in this application exemplify this process. The PRC works closely with the Research Methods Core (RMC);it provides to the RMC a stimulus and data for its methodological studies, while it incorporates the RMC innovations in the designs of substantive studies. Jointly with the Community Network Unit of the Operations Core and the ACISR community partners, the PRC conceptualizes and supports studies with the potential to bring care to large numbers elders of our community, inclusing those neglected by traditional clinical research.